//usart.c

void writeString(const char *s);
void drainTx();
void sendChar(char c);
void sendManchesterByte(char c);
void sendDecimalShort(unsigned short n);
void sendDecimalShortPad(unsigned short n, char pad);
void sendDecimalByte(char n);
void sendDecimalBytePad(char n, char pad);
void sendHexInt(int n);
void sendHexByte(char n);
void sendBinaryByte(char n);
